Multiplus II 48/5000/70 charge limited to 50A

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christiangurk asked Apr 3, '23

Multiplus II 48/5000/70 charge limited to 50A

Hi,

I have a Multiplus II 48/5000/70 connected to a 14kHw 280Ah 52V LiFePo4-Battery with JK-BMS and Venus OS on RaspberryPi. A 6kWp photovoltaik system is connected AC-coupled on the AC-IN-side. Everything is working great except during sunny periods, the maximum battery charge current seems to be limited to 50A.

I checked all settings in VenusOS, all charge limits are set to 100A. VRM portal is also showing these limits:

DVCC charge limit is switched off, BMS CCL and DCL are also set to 100A.

I also checked with dbus-spy for any secred 50A limit but found nothing. Checked DC charge limit, but also showing 70A...

Downloaded Multiplus II configuration via VRM / Device list / Remote VE Configure and checked settings in VE Configure 3:

Settings seem to be correct here (Weak AC input = off, Charge curreng 70A)

Does anybody have any idea what else to check? Would be nice, if I could use the whole 70A charging current in specific situations (short sunny periods) to quickly charge the battery...

I already tried to search other questions about this topic but didn't find a good answer. The limit of 50A seems to be a fixed barrier.

Any help is appreciated.

Multiplus-II charge current limit

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christiangurk answered · Apr 04, 2023 at 05:27 PM

Found the easy solution for my problem: I performed a restart of the Multiplus-II via VenusOS / Battery Inverter / Advanced / Restart VE.Bus system.
After the restart when I disable the "Limit charge control" switch, the Multiplus-II started to charge my battery with aroung 63A from grid (at 53.3V). This seems reasonable to me.
But thanks to all of you with your suggestions.
My gridcode is for Germany.

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pedaaa commented · Apr 10, 2023 at 08:12 AM

just had the same issue (my 3phase Multi2 5000 system was self-limited to 70A charge current)

. With the same solution to fix it: reboot the VE-Bus-System.

Now its works again normal.

@christiangurk:

Did this issue came back?! Or was this one time only?

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christiangurk pedaaa commented · Apr 10, 2023 at 10:28 AM

Hi, seems to be one time only so far. But I have my system in standby for the last couple of days, so didn't check. But seems to work normal after restart.

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kenzo christiangurk commented · Jun 23, 2023 at 07:57 PM

I have experienced the same twice now; seems like a bug. Can someone point me to another place where charge current can be configured *on the fly* that is not CCL or "Maximum charge current" in DVCC?

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Modifications Space

Node Red Space

Answer 1 · 2023-04-03T11:01:56Z

nickdb answered · Apr 03, 2023 at 11:01 AM

Any input current limits set?

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christiangurk commented · Apr 03, 2023 at 11:20 AM

AC input current limit set to 32A:

So no problem here... Maximum input power during these phases with 50A charge current limitations was around 3000W, so less than 16A, so far away from the AC input current limit...

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Answer 2 · 2023-04-03T16:09:07Z

Peter Buijs - NL answered · Apr 03, 2023 at 04:09 PM

The JK BMS maybe? It has an adjustable charge limit.

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christiangurk commented · Apr 04, 2023 at 08:39 AM

Hi Peter,

I checked all BMS settings, they are limited to 100A charge/discharge:

I also plotted already the corresponding plot from VRM portal with the BMS CCL/DCL over time, here another example from yesterday:

So CCL normaly at 100A, dropping down to around 5A during absoprtion and later going up to 100A over night. So BMS IS regulating CCL correct, but when it is set to 100A, charge current never rises above 50A. So there must be another limit elsewhere.

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Answer 3 · 2023-04-04T08:46:50Z

paulcupine answered · Apr 04, 2023 at 08:46 AM

Looks like you have 3 phase PV and single phase multi? Could it be that there isn't excess PV available on the phase that the multi is on?

What rate does the battery charge at if you set ESS to "Keep batteries charged"?

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christiangurk commented · Apr 04, 2023 at 10:11 AM

You are right, I have 3 phase PV connected to AC-IN of my Multiplus-II. ESS gridsetpoint is set to 0. So ESS tries to "hold" sum of all three phases at grid entry point ("Grid") at zero. So if there is excess power aivailable (-1331W in the first picture) then it should raise the batter charge current by this 1331W, only limited by the 70A charge current limit. That works quite well for all charge currents below 50A. So regulating gid entry point to zero works fine.

To answer your second question (good question by the way) I set the charge limit in DVCC to disabled:

Immediatly, the battery is charged with high power, peaking again at around 50A after some seconds:

So again, there seems to be a limit somewehere at 50A...

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Answer 4 · 2023-04-04T11:01:59Z

ossi answered · Apr 04, 2023 at 11:01 AM

Please try setting the ESS Setpoint to Consumption (+5000W) and check if the Inverter Charges Battery from Grid with higher current.

There is known issue about the three phase counter calculation with threephase PV inverter and single phase MP.

If the inverter doesn't charge with higher currents the Issue/ limit is in the inverter lvl - if the inverter chrages with higher currents, i propapbly know a workaround (which gridcode is activ?)

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